The action of nitrous acid with ethylamine produces:

The correct order of decreasing basic strength of the following compounds is:
$(I)$ Aniline
$(II)$ $p$-Methoxyaniline
$(III)$ $p$-Nitroaniline
$(IV)$ $m$-Nitroaniline

Which of the following is expected to be the least basic?

Ammonolysis of alkyl halides followed by treatment with $NaOH$ solution can be used to prepare primary,secondary,and tertiary amines. The purpose of $NaOH$ in the reaction is:

The reaction of $N,N'$-diphenylthiourea with concentrated $HCl$ upon heating is given by:
$(C_6H_5NH)_2C=S \xrightarrow{conc. HCl, Heat} A + B$
The unknown compounds $A$ and $B$ in the above reaction are:

Which of the following compounds is the strongest base?